Underreamer



July 17, 1928. 1,677,812 c. H. BROWN l UNDERREAMER A Filed oct. v, '1925 4 sheets-sheet 2 6b/eases aacAMAfW/v July 17, 192s.

UNDERREAMR Filed oct. '7, 1925 4 sheets-sheet 3 V66 ,Brow/7, Iwww/tana Q f @1151501 mug 1,677,812 c. H. BROWN v July 17, 1928.

c. H. BROWN UNDERREAMER 4 sheets-snm 4 Filed oct. 7., 1925 gwwmtoz n, Mm/` w mM/@0% m w amg A Patented July 17, 1928.

enanas n. mrownf', on Bnnoxnnnrnen, TEXAS.

U-NDEBREAMEB.

genauerem nemer 7, 1.925.A serial no. 61,119.

This invention appertains to wells and more particular-lp) to av novel under reamen The primary o ject ofthey invention is to ovide an improved under reamer whichl will effectively enlarge1 the hole below the well with little danger of losing the, cutters and which is. so constructed as, to underream the hole rapidly and expeditiouslyv with. a minimum amount of4 wear on the/tool.

Another object o the invention is the provision of novel means; for taking up the,

, weer in such amanner that all'danger of the cost and u.

operating thel tool after long use is climi nated, the construction oi the various, parts oi the: tool allowing a maximum amount oi' actual wear to take place before. making it necessary to re air the `tool in any way..

A further o ject of the. invention is toprovide novel means for constructing the under reamer in such amanner that a high grade o materials can be used in the construction thereof and still permit a, tool to be placed upon the market. at. a. very reasonable price,

A further object of the invention is to provide an under reamer' embodying novel cutters which are of such size that. the same may he drop forged so that they are almost to size thereby elnmnating considerable ex? pensive machine work thereon thus reducing keep of the, tool. A further o ject of the invention is the provision of novel cutters having a circular the cutters relative to one sha e on the inside so that the material close to t e saine can be worked out to the cutting edge, by hammering on the inside thereof thus eliminating the necessity of keeping the cutters in the fire a relatively- Iong length of time during the dressing thereof andthus preventing inlury thereto, the cutters permitting a relatively great quantity of material to be worn away from. the same beiore the cutters become. renderedl unfit for use.

A further object of the invention is the provision vof novel means for mounting the cutters in place and novel means for raising another whereby the loss of the cutters is precluded.

A still further object of the invention is the provision of novel means for moving the cutters to their working and non-working positions, so as to permit the expeditious removal and placing oi thetool in position.

A further object of the invention is the provision of novel means; for holding the cutters in operative position,

whereby the same will be held firmly` against movement and whereby a minimum amount of wear will take place, on the said holding means. A still; further object of the invention is to provide a novel under reamer of the above character which will be durable and eiiicient 1n use, one that will be simple. and easy to. manufacture and one which can be placed upon the market at a reasonable cost. With these and other objects in View', the invention consists lin the novel construction, arrangement and formation of parts; as will be hereinafter more specifically describedt claimed, and illustrated in the accompanying drawings,I in which drawings:

Figure l is a longitudinal section through the upper end ofthe under reamer,

Figure lais a longitudinal section', through the lower portion of one form of the proved under reamer, l i Figure Qis a bottom plan view oi" the i1r1. proved under reamer showing the cutting blades in their extended o erative position in full lines, and in their co lapsed positions in, dotted lines `Figure 3 is a detail section through the under reamer taken on the line 3 3 of Figure la illustrating the means of mounting the blades in place,

Figure l, is a detail section taken on the line of Figure l illustrating the method of holding the blades andhanging means in place in the. body of the underv reamer,Y

Figure is a detail section taken on, the

line 5-5 of Figure la looking in the direction of the arrows showing die mandrel in cross section, n

Figure 6 isa detail section taken on the line 6 6 of Figure 1 looking in the direction of' the arrows showing the formation of the upper vend oi the bodyof the under l L reamer and the mandreh Figure 7" is a detail section taken on theY line 7-7 of' Figure l looking in the direc! tion of the arrows showing the novel releasin means,

igure 8 isa longitudinal section through a slightly modifi-ed form of the tool,I

Figure 9 is au detail horizontal section through the same taken on the' line 9--9V of Figure' 8 looking in the direction oi the arrows showing the releasing means for the modified type of the tool,

Figure. 10, is a bottom plan view of the tool of the modified type showing the cutting lll Figure 13 is a detail horizontal 'section' taken on the line 13-13 of Figure 12 look- "ing in the direction of the arrows illustrating the releasing means, i j j Figure 111 is a horizontal section taken on the line 14-14 of Figure 12'looking in the direction of the arrows showing the means for andA Y "Figure 15 is a detail perspective view of one of the novel arms of the releasing de-f vice for said cutting blades.

Referring to the drawings in detail, wherein similar reference characters designate corresponding parts throughout the several views the letter A generally indicates the l... improved under reamer which comprises a body 15 having the usual shank 16 formed on the upper end thereof with the means '17 for' permitting the connectionA ofthe tool with'the well rod.

The body 15 is preferably of a circular l shape in cross section and is provided with a longitudinally extending bore 18 having a longitudinally extending slot 19'communieating therewith. rfhis slot terminates short .t of the lower end of the body and extends A i substantially to the upper end thereof.

body 15 adjacent to the lower end thereof isy i annular shoulder 25 having the axial open- The provided with internal threads 20 for the reception of the lower auxiliary body 21 which is provided with4 a shoulder 22 adja-v cent to its upper end for abutting engagement with the lower end of the main body 15. The lower auxiliary body 21 is provided with a bore 23 which opens out the upper end thereof and communicates with the bore 18 of the main body 15. As shown the auxiliary lower body 21 adjacent to its lower end is provided with a hollow circular 'shaped head 24 which defines an internal ing 26 therethrough, the purpose of which willv be hereinafter more fully described. Slidably mounted within the bore 18 Vof the main body 15, and the bore 23 of the auxiliary lower body 21 and the opening 26 is a'cylindrical rod or mandrel 27 which extends below the lower end of the head 211y and terminates substantially in the upper end of the bore 18. The mandrely adjacent to its lower end is provided with an integral stop I' shoulder 28 against whichy is fitted the mandrel cone 29kprovided for adjusting the position of the novel cutter blades 30, which are three in number and which will be herela detail horizontal section holding the operating shank in place,

inafter more fully V- described- The extreme lower end of the said mandrel 27 is threaded for the reception of a; retaining nut 31, which is utilized for holding the mandrel cone in l'position on the said mandrel and the lower end of the rod can have connected thereto to aisuitable clevis (notshown) for pulling the mally held in a raised position by a rela- 'A tivelyheavy expansion spring which is coiled about the mandrel 27, the lower end of the said spring engaging the internal shoulder 25V and a suitable" collar 33' held on the mandrel by retaining and locking lnuts 34T."

Each of the blades 30 include -substantially parallel shank portions having notches 36 in their inner faces adj acentfo the yupperend thereof defining upper and lower shoulders for a purpose, which will be hereinafter morey fully described. Below the'parallel Shanks 35, the blades arel provided with substantially arcuate body r portions 37 which'project slightly beyond theshanksdefining stop shoulders 3 8 which are adapted. to engage the lower edge of .the head 2st when the blades'are in their operative position. The lower ends of the blade bodies'' are provided with projecting cutting portions 39 andthe inner faces of the blades are arcuate shaped as indicated by thereference character 40. The inner faces ofthe shank- 35 and the'body 37 above the portions 39 and 40 are provided with inclined' faces l11 which arev adapted to vbe engaged by the cone 29 for forcing the blades apart and holding the same in their operative position against the said head 2,4. Particular attention is called to the design cf `these cutters and the way. which they set into the headland the manner' in'which the cone comes up inside of the cutters'te hold them in position. vIt can be' seen'that all of these parts are parts' of a circle and that the said yparts of the circle are all concentric and therefore' the parts: are all self centering and that any wear on the cutters orinside of Ithe head is immediatelyl taken Aupby the cone pressing onv the inner fates of the cutters. This connectionis to also hold the cutters out to gage and anyl wear occurs on the Shanks of the cutters and the'inner surface of the head causes thev projecting parts of thevcutters to push out'to 4gagethehole and instead of an old cutter having to be dressed farther and farther outward as has been the case in all other under reamers,'th'ese cutters have to be hammered a smaller amount to bring them tol gage4v when they are old and when they are new.4rvv T f. j

In under reaming whenthe blow strikes the point of the cutters against theshoulder of the hole below the well casing, the resulti the notches ant forces drive the cutters against the shoulders of the head and also the cutting edges try to dodge toward the center of the hole. VThis last force is taken up by the inner surface of the cutters resti-ng on the cone and as these cutters receive these forces on opposite sides of the cone it will be seen that the cone is supported in all directions and at all times. It will be seen that the heavy mandrel spring 82 holds the cone in between the cutters, seating them so tightly that the tool closely approximates a solid one in its rigidity. The use of the three cutters, instead of the conventional two cutters, eliminates a great deal orP trouble herebefore experienced in under roaming such as lesstof cutters, which are mainly caused by what is known as key seated holes. The blades fitting relatively close together permit the substantial entire area of the hole to be acted on at all times vthus allowing the hole to be cut as fast as the cutters are driven. y

In order to hold the cutters 30 in position I provide a novel retaining ring 42 which is provided with an annular groove 43 defining a lower shoulder 44 which lits within 36 formed in the Shanks of the cutting blades and further provided with lugs lll interitt-ing Vwith the shanks- 35, as clearly shown in Figure 3 oi' the drawings.

The retaining ring is in turn held in place by the use of suitable retainingpins 45 which are inserted through suitable openings in the head 24 directly below the lange 46 formed on the retaining ring. The pins 45 engage the retaining flange to hold the same tightly in place against the internal shoulder 25.

To change cutters it is merely necessasry to drive the retaining pins 45 out from in front of the retaining ring thereby enabling the retaining ring to vslide down when the mandrel is pulled down to its dotted position at which time the old cutters can be removed and a sharp set put on.

In order to release the cutters 30 from operative position-a novel releasing slide block 50 is provided. This release slide block 50 is mounted directly within the upper end of the bore 18 of the upper body 15 and is provided with a projecting rib 51 which is adapted to normally extend through the longitudinally extending slot 19. The outer end ot the rib 51 is inclined as at 52 and the upper edge of the rib is oppositely inclined as at 53 and inn ther provided with a lower inclined wall 52b for a purpose, which will be hereinafter more fully described. A socket 54 is formed in the extreme lower end oftheslide release block 50 and is adapted to receive the upper end of the mandrel 2T, a cushioning spring 55 being coiled about said mandrel engaging the lower end of the slide block 'and the upper locking nut 34. The inner tace of the release slide block 5() is provided with.

i a safety device.

the cutters 30 in a lowered collapsed condil tion within the circumference oit' the head 2l of the body. As 'the tool is inserted within the well casing the retaining ring (not shown) will be stripped olf Ithe body and the expansion spring 32 will normally 'tend to raise the mandrel cone .29 and the release block 50 to a raised position. As soon las the tool protr-udes beyond the lower end of the well pipe casing, the blades will assume the posit-ion place by the cone 29' and the release slide block 5() will be positioned at one side of the rigid release block 57 as shown in Figure 1.

The tool can now be used in the ordinary way and when it is desired to remove the same from the casing the tool is pulled up and the inclined lace 53 of the rib 51 will strike against the lower edge of the well casing which will force the slide block down carrying the mandrel 27 and the cone 29 therewith. As soon as the cone is forced' below the cutters, the cutters will be per mitted to rock .inwardly andas the .slide block 50 rides below the lower edge of thev rigid release block 57 the said release slide block 50 will rock inwardly owing tothe inclined 'face 53 land the entire tool can be drawn into the well casing and out of the same. By having the block 5() ,function as just described, the operation is positive, and

shown in Figure l and be held' in f to assure the releasing device being 'tooly proof in every respect the `lower inclined wall 521 is larranged to engage the lower wall of the slot 19 when the sli-de block has been forced downwardly :a predetermined distance to engage under block 57, and thus the block is bodily movable eitherby the engagement Iof the inclined wall 53 with the bottom of the casing or by the engagement of the inclined wall .52b with the lower wall of the slot should it happen that the block 50 is pushed' down the required distance, and thus the cooperation between the wall 52 and wall of the slot acts in the capacity ott In Figures 8 to 11 inclusive I have shown a slightly modilied torni of my invention in which the tool embodies the upper body G0 having the bore 61 opening out through its lower end which receives the lower body 62 having the circular head 63 defining the annular inner shoulder 64:, The mandrel 65 lll) leasing mechanism for the blades.

extends through the body 62 into the bore 6l of the upper body 6() and the lower end of the mandrel has secured thereto the mandrel cone 66 which embodies an upper tapered portion 67 for engaging the shanlrs S8 of the blades 70 and alowered tapered portion 7l for engaging the tapered inner faces of the body portions of said, blades, These blades are constructed substantially the same as the blades in preferred form with the exception of the shanlrs thereof which are provided with diametrically alined lots 72 through which extends a diametrically extending holding rod 7 3 held in place by removable pins 74: which extend through the head 63. rIlhe mandrel is slotted at a point between its end as at 75 for the reception of the said rod 7 3. The upper end is provided Vith a cap nut .76 against which a washer 77 is placed. A relatively heavy expansion spring 78 is coiled about the mandrel and rests upon the shoulder 64; and the said washer normally .holding the cone 56 in a raised position and the cutter in engagement with the head. y

Arranged within the bore Gl above the upper: end of the mandrel 65 is a releasing slide block 8O having the radially extending rib 8l which protrudes tl rough a slot 82 formed in the body 6l. rlhe lower end of the releasing slide bleek 8G provided with a socket for the reception of the cap nut 77 and the inner face of said slide block is provided with a shoulder 83 which is adapted to normally engage the rigid release block S4 secured within the bore in any desired way. This under reamer is operated in the same manner the under reamer herebefore describedand it is to be noted that when itis desired to withdraw the tool through the casing, that the tool is drawn upwardly until the rib 8l catches under the lower edge of the well casing which will force the said releasing slide block downward into engagement with the mandrel 65 forcing the cone 67 out of engagement with the blades which will permit the blade to swing inward by gravity to a releasing position at which time the block 8O will rock within the bore 6l allowing the rib 8l to pass by the said casing and thus permit the tool t0 be drawn through the same.

In Figures l2 to 15 inclusive I have shown a still further modified form of the invention in which I have provided a novel re- In this form the body 90 is provided with diam-et." cally disposed slotsQl and a cup 92 is si.a ablyA mounted within the bore 98 of the body. Arranged centrally within the bore is a depending lip A94 on each side of which is positioned the releasing arms 95 and These releasing-arms 95 and 9G are roelrably mounted upon a common pivot pin 97 carried bythe cup 92.` The upper ends of the releasing arms 95 and 96 are provided with ribs 98 which protrude through the slots 91 formed in the said body. The upper ends of these ribs 98 are provided with inclined faces 99 for permitting the same to slip by the casing when the tool is being withdrawn from the well. In practically all other respects, the tool is the same as the tool shown in VF igures 8 to llinclusive and it isto be noted that as the Vtool is withdrawn from the well casing that the lower edge of the casing will engage the ribs 99 forcing the cup 92 inward into contact with the mandrel thus forcing the same downward allowing the collapsingof the blade.

Changes in details may be made without departing from the spirit or the scope of this invention, but:

What I claim as new is: Y Y

1. An under reamer comprising a body, a plurality of arcuate cutters concentrically arranged in the lower end of the body mounted for rocking movement toward and away from the axial center of the body, a mandrel slidably mounted in the body, an adjusting cone carried by the mandrel adapted to engage the inner faces of the cutters for normally holding the same in rigid contact with the body to prevent movement thereof when the reamer is in use, a relatively heavy expansion spring coiled about the mandrel normally holding the cone in engagement with the cutters, a releasing slide block mounted within the upper end of the body, the body being provided with a longitudinally extending slot communicating with the interior of the body, a rib formed on the releasing slide block adapted to project through said slot, the inner end of the slide block being adapted to engage the upper end of the mandrel, a shoulder formed on the inner face of the releasing slide block at the lower end thereof, a rigid block normally engaging said shoulder, and adapted to engage the upper end of the slide block, when the slide block is forced downward to move the cone to cutter releasing position.V

2. An under reamer comprising a hollow body, a plurality of arcuate cutters concentrically arranged rockably mounted in the lower end of the body and adapted to protrude therefrom, a mandrel slidably mounted axially within the body, a mandrel cone secured to the mandrel adapted to engage the inner surfaces of said cutters for holding the cutters in engagement with the lower end of the body in an extended operative cutting position, an expansion spring coiled about the mandrel normally holding the cone in its raised position in engagement with the cutters, a releasing slide block roclrably mounted on the upper end of the mandrel having a rib adapted to project normally beyond the outer side face of the body having an inclined upper edge, and a shoulder at its lower Vably holding the ring in place,

inner face, a rigid block adapted to engage the shoulder when the block is in its raised position and the upper end of the block when the same is in its lowered position and the cone below the cutters.

3. An under reamer comprising a body provided with a straight bore having an annular shoulder, a mandrel extending through the bore an'd said shoulder, a retaining ring mounted upon the mandrel, means detachably holding the ring in place, cutters rockably mounted upon the ring, a cone mounted upon the mandrel for engagement with the cutters to hold the same in an adjusted position, adjusting nuts carried by the upper end of the mandrel, an expansion spring coiled about the mandrel engaging said nut and shoulder, a releasing slide block carried by the upper end of the body having a rib normally projecting beyond the body and a shoulder on the inner lower end thereof, a socket formed in the lower end of the slide block to receive the upper end of the mandrel, a cushioning spring about said mandrel engaging the slide block, and a rigid block mounted within said body for engaging a slide block when the same is in its raised position and for engaging the upper end of the slide block when the same is in a lowered position.

a. An under reamer comprising a body provided with a straight bore having annular shoulders, a mandrel extending through the bore and said shoulders, a retaining ring mounted upon the mandrel, means detachcutters rockably mounted upon the ring, a cone mounted upon the mandrel for engagement with the cutters to hold the same in an expanded position, adjusting nuts carried by the upper end of the mandrel, an expansion spring coiled about the mandrel engaging said nuts and shoulders and means for collapsing the cutters.

5. An under rearner comprising a body, cutters rockably mounted upon the lower end of the body, a mandrel slidably carried by the body, a cone on the lower end of the mandrel for engaging the cutters for normally holding the same in an extended position in rigid contact with the body, an eX- pansion spring coiled about the mandrel normally holding the same in a raised position and the cone in engagement with the cutters, a releasing slide block mounted within the upper end of the body, the body-being provided with a cut out portion communicating with the interior of the body, said block having a portion thereon adapted to extend through said cut out portion, the inner end of the slide block adapted to engage the upper end of the mandrel, a shoulder formed on the inner tace oi' the slide block at the lower end thereof, a rigid block normally engaging said shoulder, and adapted to engage the upper end of the slide block when the slide block is forced downward to move the cone to cutter releasing position.

6. in combination with a body, a collapsible cutter structure carried thereby, means controlling the movement of the critters comprising a plunger having expansible engagement with said cutters, a stationary block carried by the body, and a movable block having a plurality of inclined walls for operative ,engagement with the well casing and having a yieldable connection with said plunger for giving movements thereto.

7. An underreamer comprising a body, cutters adjustably supported by the body, a plunger for adjusting and rigidly holding the cutters in adjusted position, a mandrel connected to the plunger and yieldably and slidably supported by said body, and a slidably mounted, releasable block yieldingly engaging the mandrel in its initial movemeut and rigidly engaging the mandrel in its final movement.

8. An underreamer comprising, in combination, a body, a plurality of cutters and a retain-er connected together as a unit vtor adjustments and placement within the body, a mandrel structure controlling the relative movements of said cutters, said body provided with an inclined shoulder, and a block slidably supported by the body and having Isuitably placed inclined walls adapted to engage with a well casing for giving movements to the block for displacing the same under said shoulder, said block having an operative engagement with the mandrel.

9. An underreamer comprising, in combination, a body, a plurality of cutters and a retainer connected together as a unit for adjust-ments and placement within the body, a mandrel structure controlling the relative movements of said cutters, said body provided with an inclined shoulder and a slot contiguous thereto, a block slidably supported by the body and having suitably placed inclined walls adaptedto incline with a well casing for giving movement-s to the block or with a wall of said slot for displacing the block under said shoulder, said block having a loose connection with the mandrel in its initial movement and a rigid connection therewith in its subsequent movement.

In testimony whereof I aix vmy signature.

CHARLES H. BROWN. 

